Mopar Muscle Association UK

Think i'd go for aftermarket heads , if you get a set of iron heads you won't know if there cracked , especially under the valve springs as you won't see it , but it will rear it's head with open spring pressures , you'll also be chasin yer tail wondering why the motors smokin & using up all yer oil.

V to P clearance should'nt be a problem with either head (closed or open), you could get away with it with a thicker head gasket if you run into any problems (ideal quench is'nt the holy grail ) , the aftermarket heads won't drop the compression ratio , what they do is transfer the heat out the head faster than the iron heads , lots of ways to skin a cat.

Ive got a pair of 906 heads Im no longer using. pressure tested,valves reseated and skimmed to give about 9.4 to 1 with flat tops. ran 13.04 on numerous occasions. if any good let me know

Bearing in mind I've spent $400 on an FBO ignition kit already

where did you get the FBO kit from ? can't remember it being from me and $400 seems high ?

I doubt very much the valve seat damage was due to unleaded fuel. You would have to do tens of thousands of miles to have an effect and I doubt they would look as you describe.

Any chance of a photo of the damage? Could it be due to those cylinders being too lean?

I would stick with stock iron heads if i were you and considering the intended use of the vehicle. But you don't want a set that needs a lot of work (valve guides etc).
I have seen good iron heads sell for as little as £40. I tried to get shot of a pair of 906 heads for a mate a while ago and no-one wanted them. Not sure if he still has them or if he scrapped them.

I threw a perfectly good pair away. Asked on here, no one wanted them.
Off a low mileage Jenson, Joe had in his shop.

Plugs talk a thousand words , stick a pic up.

nick.stratta wrote:Here's a pic of the head

Ok so what do you think might have caused one exhaust valve shown to turn a very pale colour and yet the one in the other picture is black?

One is too rich (or burning oil) and the other too lean. The pale one is the lean. It has been getting hot enough to burn the carbon white.

You sure the valve seats will not clean up with a bit of work with the old grinding paste?

Use a steel stock head with the same CC combustion chamber as ally heads due to the heat dissipation will need higher compression ratio

I pretty sure I have a pair of 452 open chamber heads here but while the valve seats will be ok for unleaded the open chambers will drop your compression.

Valve seats will need sorting out though

But you can have em for free if they are any use

nick.stratta wrote:Here's a pic of the head

Top pic of head is to show difference between a good sated valve and the bottom shows the valve with no seat left, valve is right back into head.

So these are two different heads, the one with black valves is from a different motor.

Dave wrote:One is too rich (or burning oil) and the other too lean. The pale one is the lean. It has been getting hot enough to burn the carbon white.

You sure the valve seats will not clean up with a bit of work with the old grinding paste?

Just a theory, is there a possibility that the heatup velve in the exhaust being stuck in the closed position for a prolonged period could have overheated the valves and seats enough to burn them out???
on stock manifolds, pass one has a butterfly flap which was possibly closed and stuck or partially closed.